yesterday in the french section I submited an idea that I also want to explain here because there is no reason not to do that.
My idea is simple and begin with an observation that I recently made: Today it's easy to listen all the music with services like spotify or deezer. It's also easy to listen good quality music with Hifi. But it's not very simple to listen all music of spotify for example on hifi system.
But as you can see, none of those solution is perfect. Either it's not compatible with good quality music or it's too expensive (Sonos).
I think that it could be interesting to make an open source project in order to build a system to set-up an home wireless musical network, like Sonos.
You could first define a protocol, that way everybody could work on a custom receiver or emitter.
Using arduino this project could allow to listen music from spotify without PC being directly linked to the internet box.
This kind of project needs a lot of different competences : Hardware, software, smartphone application (for command), design...
I hope to find people interested in this project. Please comment this topic or contact me directly.
My first reaction to your post was that it sounds like a great open source project. I agree with virtually all of your points. And your grammar is better than many of the posts around here.
Then I started thinking about what an Arduino would need to do to make this happen. I'm not an AVR expert, but I'm very familiar with streaming audio, such as VoIP. Streaming requires managing multiple buffers of audio. I don't believe that the AVR instruction set and the limited RAM resources would make for a good streamer. There are other CPUs that would be a better choice for this application.
Even if you could stream PCM (raw, unencoded audio), I doubt that you'd ever be able to implement a codec for any other format. A streaming device should be able to do this.
Maybe someone with more AVR experience can convince me otherwise. But until then, I'd recommend you find another processor for this project.